Hand tool for crimping electrical connectors onto conductors



H. W. DEMLER Jan. 17, 1961 HAND TOOL FOR CRIMPING ELECTRICAL CONNECTORSONTO CONDUCTORS Filed May 19, 1959 2 Sheets-Sheet l Jan. 17, 1961 w,DEMLER 2,968,043

HAND TOOL FOR CRIMPI'NG ELECTRICAL CONNECTORS ONTO CONDUGTORS Filed May19, 1959 2 Sheets-Sheet 2 fi I 22, I

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:b i" INVENTOR. Henry M flem/er BY FM United States Patent HAND TOOL FORCRIMPING ELECTRICAL CONNECTORS ONTO CONDUCTORS Henry W. Dernler,Lebanon, Pa., assignor to AMP Incorporated, Harrisburg, Pa.

Filed May 19, 1959, Ser. No. 814,339

Claims. (Cl. 1-215) Electrical connectors of the ferrule type may becold forged onto conductors in various ways including actuation ofcrimping dies by explosive force. An application filed in the name ofWilliam F. Broske (CMS 123114-A), Serial No. 806,093, filed April 13,1959, teaches the concept of actuating connector crimping dies by firingan explosive cartridge internally, i.e. with a primer located inside thecartridge.

It is an object of this invention to provide a tool such as referred toabove which is compact, light-weight, and easily operated. It is also anobject of this invention to provide such a tool having a firingmechanism which is spring loaded during the firing cycle, but is sodesigned that the spring loading mechanism is inactive during thecrimping stroke. In previously known tools, the explosive force operatesthe dies so as to place the spring in tension and cause fatigue. Thetool illustrated by the present invention is designed so that the springis inactive during the crimping or explosive cycle.

It is a further object of this invention to provide such a tool whereinthe tool can only be actuated by positive operation. In many of theexplosive tools shown in the prior art, the tool may be placed in acocked position before it is fired. Thus the possibility exists that theoperator may cock the tool and then lay it down in this cocked position.However, in the tool shown in this application, the operator cannot cookthe tool and leave it lying around, since the motion to put the toolinto firing position must automatically cause the tool to be fired orelse the spring means will cause it to return to its inactive position.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetaileddescription when taken in conjunction with the drawings in whichthere is shown and described an illustrative embodiment of theinvention; it is to be understood, however, that this embodiment is notintended to be exhaustive nor limiting of the invention but is given forpurposes of illustration in order that others skilled in the art mayfully understand the invention and the principles thereof and the mannerof applying it in practical use so that they may modify it in variousforms, each as may be best suited to the conditions of a particular use.

In the drawings;

Figure 1 is a perspective view of a tool embodying principles of thisinvention;

Figure 2 is a fragmentary View similar to Figure 1, partially brokenaway;

Figure 3 is a plan view taken along plane 3--3 of Figure 1;

Figure 4 is a sectional view taken along plane 4-4 of Figure 3;

Figure 5 is a sectional view taken along plane 5--5 of Figure 3.

As shown in the drawings, the basic unit of the tool comprises aO-shaped head 10, preferably a metal of ade- 2,968,043 Patented Jan. 17,test quate strength, with a pistol-grip type of handle 12 securedthereto (or integral therewith) at an angle to the longitudinal axis ofthe frame. Located in one bight of the inside surface of the head is afixed die 14. An opening 16 in the head opposite the fixed dieaccommodates a slidable ram 18 with a movable die 20 on one end thereof.The dies 14 and 20 are thus operatively disposed and relatively movableto deform an electrical connector C placed therebetween (note Figure 3).

The opening 16 may be counter bored as to accommodate a firing chamber21. Although the firing chamber 21 could be integral with the head 10,the preferred embodiment shows it as a separate piece from the frame soit may be made of material more suitable for a firing chamber, e.g.stainless steel. A lock nut 22 retains the firing chamber 21 in theframe. A threaded cap 24 fits over the end of the firing chamber 21, andhas a spring loaded locking latch 26 pivoted thereto with a hook 27 onone end which fits into a detent 28 on the cap 2 t to form a releasablelocking means. The internal bore of the firing chamber 21 accommodatesan internally fired cartridge 30. This cartridge is described in apatent application filed February 17, 1959, in the name of William F.Broske, Serial No. 793,814. As set forth in the application, thecartridge assembly includes an internal plug 32, an explosive charge: 34and a primer 36 located within the internal plug 32.

As shown in the drawings, the ram 18 is disposed internally of thecartridge 30. A detonating pin 38 is carried on the free end of the ramwhereby movement of the ram in a direction toward the priming meanscauses the detonating pin to strike the primer 36 and thus detonate thecartridge.

An opening 40 in the head 10 (parallel to the opening 16) contains ashaft 42 slidably disposed therein. The shaft 42 has a pair of handles44, 46 (Figure 1) projecting from one end thereof at right angles to theshaft. These handles may be used to grip the shaft in moving it back andforth. A hollow section 48 in the frame 10 accon1- modates a pair oflevers 50 and 52. Lever St is pivoted at one end to the frame at 54 withits opposite end projecting into the path of the movable die 20. In itsoperative position, one side of the lever bears against the opening inthe frame and the opposite side bears against the movable die 20. Thesecond lever 52 is also pivoted within the frame at an intermediatepoint on the lever by means of a pivot pin 56. In its operativeposition, the point 58 of the lever bears against a shoulder 69 in thenonworking or rearward face of the movable die. As shown in Figure 3,these levers cooperate releasably to lock the die 20 in its contact orpro-fired position.

A first spring 62 is secured between the first lever 5i) and the tube 42and is at rest in the position shown in Figure 3. A second spring 64 issecured between the pivot pin 54 and the bottom part of the lever 52 andis at rest when the levers 5d and 52 lock the die 2 in place. A tab 66projects from the shaft d2 to provide an actuating means for the second.lever 52. As seen in Figure 4, a slot 67 in the tube 42 forms a trackfor the lever 50. Thus the tab 66 does not affect the lever but tripsthe lever 52 when moved rearwardly with the tube 42. A housing 68 issecured to one end of the C-shaped frame and has a pair of pivotedhandles 79, each operating a pivoted arm 72 which grip the conductor andhold it in position during the crimping operation.

0perati0n.A connector C is inserted between the relatively movable dies14 and 20. A conductor is inserted therein and hooked into place by thearms 72 on the housing 68. The cartridge 30 is inserted into the firingchamber 21 so that it encompasses one end of the ram 18. The cap 24 isthreaded. and locked onto the back of the firing chamber. The die 20 ismanually moved forwardly until it is locked between the levers 50 and52. The tool is now ready to be fired.

In firing, the operator grips the handles 44, 46 in one hand and thepiston grip 12 in the other. Pulling the handles rearwardly causes theshaft 42 to move in a direction away from the fixed die 14. With thelever 52 looking the movable die 20 against rearward action and themovable die 20 holding the lever 50 against rearward action, the motionof the shaft 42 serves to extend the spring 62 and place it in tension.When the spring as is fully extended, the tab 66 trips the bottomportion of the lever 52 and causes it to rotate counter-clockwise. Whenthe lever 52 is rotated counter-clockwise, the ram 18 and movable die 20is released. The spring contacts moving the lever 50 against the die 20to drive the die 2% and ram 18 in a rearward direction toward the primer36. The lever 50 moves clockwise out of the path of travel of the die29. Rearward travel of the die 20 and the ram 18 causes the detonatingpin 38 to be impacted against the primer 36. This explodes the primerand, in turn, combustion of the charge 34 drives the ram 18 and die 20forwardly toward the conductor and the connector to crimp them togetherby cooperation of the die 14 and the die 20. It is noted that in theforward travel of the ram, both levers t} and 52 are out of the path ofthe die. The connector and conductor are then removed from the die andthe spent cartridge is also removed.

Changes in construction will occur to those skilled in the art andvarious apparently different modifications and embodiments may be madewithout departing from the scope of the invention. The matter set forthin the foregoing description and accompanying drawings is offered by wayof illustration only. The actual scope of the invention is intended tobe defined in the following claims when viewed in their properperspective against the prior art.

I claim:

1. A tool for crimping electrical connectors including: a first die, asecond relatively movable die cooperating with the first die to crimp aconnector therebetween, explosive means for operating said relativelymovable die, means for detonating said explosive means including a firstpivoted lever adapted to urge the movable die toward the explosivemeans, a ram on said movable die adapted to strike the explosive meanswith the necessary detonating force, a spring means for urging saidlever against said die in a direction calculated to drive the die andthe ram against the explosive means, and releasable means forrestraining the die until the spring is loaded to a predeterminedamount.

2. A tool of the character described having an explosive means therein,including a movable member capable of moving longitudinally in onedirection to accomplish work, and in the opposite direction to detonatethe explosive means, means for urging said member in a direction todetonate the explosive means, said means including a pivoted leverbearing against the movable member, spring loaded means for actuatingthe lever in a direction calculated to drive the member in the explosivedetonating direction, and releasable locking means for retaining saidmovable member in fixed position until the spring is sufiiciently loadedso as to drive the member into the explosive detonating position withsufficient force to detonate the explosive.

3. A device for firing an internally fired cartridge operated toolhaving a pair of cooperative, relatively movable dies including: a leverpivoted at one end, the free end of the lever bearing against themovable dies, a second lever pivoted intermediately of its ends with oneend bearing against the opposite side of the movable die, a springbiased lever with one end projecting into the path of said die, aspring-loaded member movable longitudinally toward the spring-biased endof the lever, means on said member for causing actuation of the secondlever into a position wherein it is displaced from the path of themovable die, and spring means on the said movable member between themovable member and the first lever, said spring means adapted to bestretched to a predetermined degree to cause the first lever to actuatethe movable die after the second lever has been displaced from the pathof the movable die.

4. An explosively-operated device for performing useful work including aframe member, a handle on said frame, a pair of relatively slidable diespositioned in said frame, means in said frame for generating anexplosive force, one of said dies having a ram secured thereto with adetonating pin on the free end of the ram, said ram movable toward saidmeans for generating an explosive force, and means for driving said diein a direction whereby the detonating pin is driven against the meansfor generating an explosive force to detonate it at the end of thestroke, said means for driving said die being inoperative unlessactuated with sutficient force to cause the die and ram to be drivenrearwardly to the full extent of their stroke.

5. A tool for crimping electrical connectors onto conductors, includinga C-shaped frame, a handle secured to said frame, a pair of relativelymovable dies within the C of the frame, a ram on at least one of saiddies, said ram extending into the frame, a detonating chamber in saidframe adapted to receive one end of said ram and to permit said ram toslide longitudinally therein as to the die is moved longitudinally,means for actuating said movable die including a pair of levers, saidfirst lever pivoted at one end with the opposite end bearing against theworking face of the die, said second lever pivoted intermediate its endswith one arm bearing against the nonworking face of the movable die andspring-biased into the path of the die, a spring means securedintermediate the ends of said first lever, the other end of said springbeing secured to a spring operating means, said spring operating meansactuatable to place the spring under a predetermined tension, and meanson said spring operating means for tripping the second lever after thespring operating means has placed the spring under the predeterminedtension, whereby the spring operating means loads the spring means tothe predetermined degree, and the second lever is swung out of the pathof the die to release the die for rearward travel, thus causing thespring means to pivot the first lever against the movable die to drivethe movable die toward the detonating means.

No references cited.

